Don't fail to highlight when Rouge doesn't have a lexer

1 files changed, 27 insertions, 7 deletions

diff --git a/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb b/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
index 48ebc81cf82..b1370bca833 100644
--- a/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
+++ b/spec/lib/banzai/filter/syntax_highlight_filter_spec.rb
@@ -3,15 +3,35 @@ require 'spec_helper'
 describe Banzai::Filter::SyntaxHighlightFilter, lib: true do
   include FilterSpecHelper
 
-  it 'highlights valid code blocks' do
-    result = filter('<pre><code>def fun end</code>')
-    expect(result.to_html).to eq("<pre class=\"code highlight js-syntax-highlight plaintext\"><code>def fun end</code></pre>")
+  context "when no language is specified" do
+    it "highlights as plaintext" do
+      result = filter('<pre><code>def fun end</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight plaintext"><code>def fun end</code></pre>')
+    end
   end
 
-  it 'passes through invalid code blocks' do
-    allow_any_instance_of(Rouge::Formatter).to receive(:format).and_raise(StandardError)
+  context "when a valid language is specified" do
+    it "highlights as that language" do
+      result = filter('<pre><code class="ruby">def fun end</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight ruby"><code><span class="k">def</span> <span class="nf">fun</span> <span class="k">end</span></code></pre>')
+    end
+  end
+
+  context "when an invalid language is specified" do
+    it "highlights as plaintext" do
+      result = filter('<pre><code class="gnuplot">This is a test</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight js-syntax-highlight plaintext"><code>This is a test</code></pre>')
+    end
+  end
+
+  context "when Rouge formatting fails" do
+    before do
+      allow_any_instance_of(Rouge::Formatter).to receive(:format).and_raise(StandardError)
+    end
 
-    result = filter('<pre><code>This is a test</code></pre>')
-    expect(result.to_html).to eq('<pre>This is a test</pre>')
+    it "highlights as plaintext" do
+      result = filter('<pre><code class="ruby">This is a test</code></pre>')
+      expect(result.to_html).to eq('<pre class="code highlight"><code>This is a test</code></pre>')
+    end
   end
 end